NSTK · 01.2026Independent supplement reference
NutriStack
Edition 1.0Updated August 1, 2026

Supplement × Prescription·Evidence index

Flecainide and Potassium: what the published research says

PubMed indexes 8 records that name Flecainide and Potassium together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.

Read this first

An evidence index, not guidance.

Every statement below is attributed to a named, dated, linked source.

This page lists published research relevant to Flecainide and Potassium. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.

The research

8 studies naming Flecainide and Potassium.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Preferential depression of conduction around a pivot point in rabbit ventricular myocardium by potassium and flecainide.

Journal of cardiovascular electrophysiology · 2000 · PMID 10749349

Comparative StudyAnimal study

“Lowering the amount of excitatory current by potassium or flecainide preferentially impairs U-turn conduction. The occurrence of long delays and conduction block at pivot points may explain the mode of action of Class I drugs.”

Danse et al. · Authors' conclusion

Names both Flecainide and Potassium in its title.

Comparison of the effects of restacorin and flecainide on various cardiac transmembrane potassium currents.

Acta physiologica Hungarica · 1996 · PMID 9219622

Comparative StudyAnimal study

“The delayed rectifier potassium current was depressed markedly by flecainide and moderately by restacorin. These results suggest that although flecainide and restacorin cause similar changes in the various transmembrane ionic currents, there are some differences between the effects of the two antiarrhythmic compounds.”

Németh et al. · From the abstract

Names both Flecainide and Potassium in its title.

Molecular basis of hERG potassium channel blockade by the class Ic antiarrhythmic flecainide.

Journal of molecular and cellular cardiology · 2015 · PMID 26159617

Human subjects

“On the other hand, the molecule could readily form π-π stacking interactions with aromatic residues and particularly with F656. We conclude that flecainide accesses the hERG channel from the cell interior on channel gating, binding low in the inner cavity, with the S6 F656 residue acting as a principal binding determinant.”

Melgari et al. · From the abstract

Names both Flecainide and Potassium in its title.

Effects of ambasilide, quinidine, flecainide and verapamil on ultra-rapid delayed rectifier potassium currents in canine atrial myocytes.

Cardiovascular research · 2000 · PMID 10727663

Animal study

“Ambasilide, quinidine, flecainide and verapamil inhibit I(Kur.d), with preferential action on the open state. I(Kur.d) inhibition may play a role in antiarrhythmic effects in canine atrial arrhythmia models. Comparisons between the effects of these drugs on I(Kur.d) and previously studied effects on I(Kur) suggest potential opportunities for investigating the molecular structural determinants of drug-blocking action on atrial-specific ultrarapid delayed rectifiers.”

Yue et al. · Authors' conclusion

Names both Flecainide and Potassium in its title.

Block of delayed rectifier potassium current, IK, by flecainide and E-4031 in cat ventricular myocytes.

Circulation · 1990 · PMID 2114236

Animal study

“IK block by E-4031 most likely underlies the drug's potent class III antiarrhythmic properties. On the other hand, flecainide block of IK during an action potential would tend to prolong repolarization, but this effect may be obscured by concomitant block of plateau Na+ channels to produce little or no change in action potential duration, consistent with its class IC classification.”

Follmer et al. · From the abstract

Names both Flecainide and Potassium in its title.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

NutriStack

Track what you actually take.

NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Flecainide, Potassium, and several hundred other substances.

The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.